IRS1 and metabolic dysfunction-associated steatohepatitis: Notably, Tn and Ts housed, NASH diet fed mice, despite differences in NAFLD severity, had similar hepatic expression of insulin signaling (Pparγ and Irs1) and lipid metabolism-associated genes (Lxrα, Lipe, Chrebp, and Srebp) (Supplementary Figures 2K–L).